More than a year after abortion was decriminalised in Mexico City, abortion opponents hope the Mexican supreme court will reverse the legislation in a decision that could reverberate across Mexico and Latin America.

Mexico's highest court heard public testimony in the spring, and is expected to rule as early as this month on the constitutionality of the local abortion measure.

The Federal District is governed by the left-leaning Party of the Democratic Revolution. Through its control of the city assembly, the party in April 2007 legalised abortion in the city for women who are up to 12 weeks pregnant.

The measure is unusual because it legalises abortion in the capital. Except in cases of rape or risks to the mother's life, abortion remains illegal in most of rest of this devoutly Roman Catholic nation.

States in Mexico set their own policies on abortion rights, and only Yucatan in Mexico's far south has allowed abortion in cases of extreme poverty.

University studies estimate between 500,000 and 1 million abortions take place in Mexico annually, but most are of questionable legality.

The Catholic Church and anti-abortion activists want the high court to strike down the Mexico City measure. They argue that life begins at conception and carrying out an abortion amounts to a taking of life that violates Mexico's constitution.

"A person's life has such a great value that we cannot take it, we are not the owners," insists Ana Elena Cantu, a city legislator in the northern industrial city of Monterrey and an anti-abortion leader in Mexico.

But the 11 members of Mexico's high court may look beyond the constitutional question.

"It is not a philosophical debate. It is mostly about the criminality. Should you or should you not be penalising it," said Miguel Sarre, a university law professor at the Autonomous Technological Institute of Mexico.

In prior rulings, Mexico's high court declared abortion to be a crime but said it should not be penalised.

That ruling mollified both sides, but such a broad decision is unlikely this time, Sarre said, partly because Mexico City is drawing women in from other parts of the nation for abortions.

Since May 2007, 12 participating public hospitals in Mexico City have performed more than 12,000 free abortions, and are averaging about 35 to 40 such procedures per day, according to the city's director of emergency medical services, Dr. Arturo Gaytan. Most of the women are poor, he said.

"There isn't a way to measure this. What was clandestine is now authorised. We don't know what the measure is outside these medical units," Gaytan said.

Women who could afford it traditionally went to private clinics for abortions that technically were illegal. Today, these clinics continue to perform the procedures, but women who visit them have more recourse.

"If something happens, your family or you have legal grounds to allege negligence," said Daphne, a 23-year-old law student who first spoke to McClatchy Newspapers in March 2007 as she readied to have an abortion just weeks before it became legal.

Speaking again on condition that her last name be withheld to protect her privacy, Daphne said she would still choose a private clinic today for an abortion because "people are still afraid of the (public) institutions".

To combat that image of poor quality, city health officials point to the number of recorded deaths of mothers during the procedure. In 2005, 15 women died during a reported abortion, eight in 2006, one in 2007 and none in 2008, Gaytan said.

"What this suggests is that procedures in clandestine areas have disappeared and given way to this," he said.

Of the now-decriminalised abortions at public hospitals, 39 percent involved women who already have children and cannot afford another. Students represented almost 27 percent of the women seeking abortions, while 20 percent were maids and domestic workers. In 58 percent of the cases, the women seeking an abortion had an intrauterine device implanted to prevent another unwanted pregnancy.